Circuit Breakers

Part Number	Description / PDF	Quantity
T21-2-10.0A-01-31AL-V Sensata Technologies – Airpax	CIR BRKR MAG-HYDR 10A TOGGLE	0
4411.0099 Schurter	CIR BRKR THRM 12A 277VAC 28VDC	12
N11-B0-24-610-121-D3 Carling Technologies	CIR BRKR MAG-HYDR 10A 240VAC	5
4420.0728 Schurter	CIR BRKR THRM MAG 5A 480V 65V	0
AA1-B0-34-620-3B1-C Carling Technologies	CIR BRKR 20A 277VAC 80VDC	0
IULK1-1-62-30.0-C-01 Sensata Technologies – Airpax	CIR BRKR MAG-HYDR 30A LEVER	0
2800843 Phoenix Contact	CIR BRKR 10A 277VAC 50VDC	2836
4430.1334 Schurter	CIR BRKR THRM 8A 240VAC 60VDC	0
1019947 Phoenix Contact	CIRCUIT BRAKER 40A	149
C30A2P-GFI American Electrical, Inc.	CIR BRKR MAG-HYDR 30A 240VAC	0
4430.0904 Schurter	CIR BRKR THRM 16A 240VAC 60VDC	16
2800922 Phoenix Contact	CIR BRKR SOLID STATE 1A 24VDC	3308
2-6400-IG1-P10-SI-5A E-T-A	CIR BRKR THRM 5A 250VAC 28VDC	0
MRCBP-24-H-40A OptiFuse	HOR. BRACKET - TYPE III, 40A 24V	190
4435.0027 Schurter	CIR BRKR THRM 50MA 240VAC ROCKER	10
4435.0029 Schurter	CIR BRKR THRM 2A 240VAC 32VDC	354
330-T25S2U20 c3controls	MPCB W/ THRML/MAG TRP 16 ~ 20A	200
IULK1-1REC4-52-60.0-K-01 Sensata Technologies – Airpax	CIR BRKR MAG-HYDR 60A LEVER	0
2907692 Phoenix Contact	CIR BRKR 32A 480VAC 125VDC	30
104-PR3-1.8A E-T-A	CIR BRKR THRM 1.8A 250VAC 48VDC	0

Circuit Breakers

1. Overview

Circuit breakers are automatic electrical switches designed to protect circuits from damage caused by overloads or short circuits. Unlike fuses, they can be reset after tripping. Modern circuit breakers ensure electrical safety, prevent equipment damage, and maintain system reliability in residential, commercial, and industrial applications.

2. Main Types and Functional Classification

Type	Function Features	Application Examples
MCB (Miniature Circuit Breaker)	Thermal-magnetic protection, <100A rating	Residential wiring, lighting circuits
MCCB (Molded Case Circuit Breaker)	Adjustable trip settings, 10-2500A rating	Industrial machinery, HVAC systems
ACB (Air Circuit Breaker)	High fault current interruption, 400-6300A rating	Power distribution in data centers
RCCB (Residual Current Circuit Breaker)	Earth leakage protection (5-500mA sensitivity)	Outdoor outlets, swimming pool equipment
RCBO (Residual Current Breaker with Overcurrent)	Combines overload, short-circuit, and leakage protection	Hospital equipment, construction sites

3. Structure and Components

Typical components include: - Enclosure: Flame-retardant insulating material housing - Contacts: Silver alloy for high conductivity - Trip Mechanism: Bimetallic strip (thermal) and electromagnetic coil (magnetic) - Arc Extinguisher: Multi-plate chamber for arc suppression - Operating Lever: Manual ON/OFF control with position indicators

4. Key Technical Parameters

Parameter	Description	Importance
Rated Current (In)	Maximum continuous current without tripping	Determines load capacity
Rated Voltage (Un)	Maximum operating voltage	Ensures insulation safety
Breaking Capacity (Icu)	Maximum fault current interrupting capability	Prevents catastrophic failure
Tripping Characteristics	Time-current curve (B/C/D types)	Matches load requirements
Pole Number	1P to 4P configurations	Determines phase protection

5. Application Fields

Power distribution: Residential panels, commercial switchboards
Industrial equipment: Motors, transformers, CNC machines
Renewable energy: Solar inverters, wind turbine systems
Transportation: EV charging stations, rail traction systems

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Schneider Electric	Acti 9 series	Modular design, 0.5-125A range
Siemens	5SJ series	High short-circuit withstand, DIN rail mount
ABB	Emax series	Smart connectivity, up to 6300A
General Electric	THQL series	UL-certified, industrial motor protection

7. Selection Guidelines

Key considerations: - Match rated current to load requirements (125% safety margin) - Select tripping curve (Type B for resistive loads, C for motors) - Verify breaking capacity against system fault levels - Consider environmental factors (temperature, altitude) - Ensure compliance with standards (IEC 60898, UL 489) - Example: For a 20kW motor (400V), select MCCB with 63A rating, Type C curve, 50kA breaking capacity

8. Industry Trends

Emerging trends include: - Smart grid integration with IoT-enabled monitoring - Compact designs for space-constrained applications - Eco-friendly materials with halogen-free construction - Integration with renewable energy systems - Predictive maintenance via AI-powered diagnostics - Increased adoption of DC circuit breakers for EV infrastructure